"The Exercise of Construction Must Consider Both the Disclosure and the Claims"

Guest Tek Interactive Entertainment Ltd v Nomadix Inc 2021 FC 276 McHaffie J

2,600,760 / 2,750,345

There has been an on-going debate in the case law as to whether recourse to the disclosure is always permissible in claim construction, or is permissible only if the claim terms are ambiguous. In Guest Tek McHaffie J contributed to this debate with a careful and principled analysis of the jurisprudence, including a discussion of a somewhat ambiguous paragraph in Tearlab 2019 FCA 179 [33] that both parties had relied on.

McHaffie J concluded as follows:

[47] Ultimately, I conclude from the foregoing that the exercise of construction must consider both the disclosure and the claims, with the claims being purposively construed in the context of the patent as a whole and in light of the CGK of the POSITA. However, the focus remains on the language of the claims, which defines the scope of the monopoly. The disclosure should not be used to enlarge or contract the scope of the claims, particularly through the addition of words or limitations not found in the claims.

I agree entirely both with McHaffie J’s conclusion and his analysis, which I’ve reproduced below the fold. I’ve argued to that effect in my posts on the topic (though I somehow completely missed the key passage from TearLab in my post on that decision). I am having a hard time keeping track of where every FC judge stands on the issue, but my sense is that the recent trend is to the view that the claims must always be construed in light of the specification as a whole, as McHaffie J concluded: see eg Grammond J in Bauer Hockey 2020 FC 624 (here) and Manson J in Viiv v Gilead 2020 FC 486 (here).

(1) Recourse to the disclosure in claims construction

[41] Paragraph 33 from Tearlab [2019 FCA 179], reproduced above, prompts some further discussion, as the parties and experts each referred frequently to passages in the disclosure in support of their arguments on construction. Justice de Montigny reaffirms that claims construction requires that the disclosure and the claims must be “looked at as a whole. ”In support, he quotes the oft-cited principle from Consolboard [[1981] 1 SCR 504] that “[w]e must look to the whole of the disclosure and the claims to ascertain the nature of the invention” and a reasonable and fair construction [emphasis added]: Consolboard at p 520, cited with approval in Teva [2012 SCC 60] at para 50; in Monsanto Canada Inc v Schmeiser, 2004 SCC 34 at para 18; in Whirlpool [2000 SCC 67] at para 49(g); and recently by the Court of Appeal in Western Oilfield Equipment Rentals Ltd v M-I LLC, 2021 FCA 24 at para 16.

[42] However, Justice de Montigny also cited the caution from Whirlpool that a Court may look to the disclosure and drawings to “understand ”the words of a claim but not to “enlarge or contract the scope of the claim as written”: Tearlab at para 33, citing Whirlpool at para 52. Of course, any construction given to the words in a claim will affect the scope of the claim: Whirlpool at para 49(h). I therefore take the rule against using the disclosure to “enlarge or contract” the claim as written to preclude adding words, elements, or limitations not found in the claim, or giving the words a meaning they cannot reasonably bear when interpreted in the context of the patent as a whole.

[43] Justice de Montigny also alludes to the principle that the specification will be relevant where there is “ambiguity” in the claim, citing AstraZeneca Canada Inc v Apotex Inc, 2017 SCC 36 at para 31. The Federal Court of Appeal in its 2016 decision in Tadalafil adopted the approach that “recourse ”to the rest of the specification is unnecessary where the words in the claim are “plain and unambiguous”: Mylan Pharmaceuticals ULC v Eli Lilly Canada Inc, 2016 FCA 119 at para 39 [Tadalafil], quoting The Hon RT Hughes, D Clarizio & N Armstrong, Hughes and Woodley on Patents (Toronto: LexisNexis Butterworths, 2005) (loose-leaf 2d ed) at p 312. The Court of Appeal concluded the trial judge in that case erred in even referring to the disclosure when construing the claims, given the lack of ambiguity in the relevant claim, saying such reference was precluded:

[39] In my view, the judge erred in referring to the specification when construing the claims of the ‘377 patent. The rules of patent construction preclude reference to the specification when the claims are clear, and also improper if it varies the scope of the claims: Hughes and Woodley on Patents, p. 312:

In construing a patent, the claims are the starting point. The claims alone define the statutory monopoly and the Patentee has a statutory duty to state, in the claims, what [t]he invention is for which protection is sought. In construing the claims, recourse to the rest of the specifications is (1) permissible to assist in understanding the terms used in the claims; (2) unnecessary where the words [are] plain and unambiguous and (3) improper to vary the scope or ambit of the claims.

[Emphasis added.]

The final sentence of the foregoing passage from Hughes and Woodley on Patents is itself simply a restatement of the Court of Appeal’s earlier decision in Dableh v Ontario Hydro, [1996] 3 FC 751 (CA) at para 30. This passage from Tadalafil was referenced by the Court of Appeal recently without adverse comment about its applicability: Hospira Healthcare Corp v Kennedy Trust for Rheumatology Research, 2020 FCA 30 at paras 21–22.

[44]     A similar approach was taken by the Court of Appeal shortly after Tearlab in Tetra Tech EBA Inc v Georgetown Rail Equipment Company, 2019 FCA 203. There, the Court of Appeal held that a Court may look to the whole of the specification to understand a claim term or “confirm ”a construction arrived at upon consideration of the claims, but not to enlarge or contract the scope of the claim as written: Tetra Tech at paras 86, 103–104. The Court of Appeal criticized a construction by this Court that relied on expert testimony and a passage in the disclosure, and not the language of the claim, stating that recourse to the disclosure should be undertaken only in cases of ambiguity: Tetra Tech at paras 91, 100–103.

[45] There is in my view some tension between the principle that claims construction requires the disclosure and the claims be looked at as a whole, and the notion that “recourse ”to the disclosure is only permissible when the claims are ambiguous. The purpose of beginning the construction exercise with the disclosure, and requiring consideration of the disclosure and the claims as a whole, is presumably to recognize that the disclosure assists and influences the purposive understanding of the claim terms in their context: Consolboard at p 520; Whirlpool at paras 49(c)–(g), 52; Tearlab at para 33. If this is so, it is difficult to reconcile with the requirement that the POSITA—and the parties, experts, and Court—cannot refer (or have “recourse”) to those very parts of the disclosure that assist in understanding the claim terms unless they first conclude the terms are ambiguous. As Justice Binnie recognized in Whirlpool, determining whether a term is ambiguous may itself require “careful review” of the disclosure: Whirlpool at para 52. I note that in Monsanto, the Supreme Court engaged in claims construction with reference to the disclosure without any prior determination that the claims were ambiguous: Monsanto at paras 17–19.

[46] Indeed, terms used in a claim will often be expressly discussed or defined in the disclosure, in keeping with the principle that the patentee may “act as his own lexicographer”: Kramer v Lawn Furniture Inc, [1974] FCJ No 100, 13 CPR (2d) 231 at para 16. The rule against recourse to the disclosure presumably does not require the POSITA to find an ambiguity in a claim term before having recourse to the patentee’s definition of the term in the disclosure, or the patentee’s ability to define their lexicon would be significantly undermined.

[47] Ultimately, I conclude from the foregoing that the exercise of construction must consider both the disclosure and the claims, with the claims being purposively construed in the context of the patent as a whole and in light of the CGK of the POSITA. However, the focus remains on the language of the claims, which defines the scope of the monopoly. The disclosure should not be used to enlarge or contract the scope of the claims, particularly through the addition of words or limitations not found in the claims.

[48]     As discussed below, in this case I conclude there are no terms where consideration of the disclosure suggests a construction different than that suggested by the face of the claim read in light of the patent as a whole. In two cases—the term communications between in the ’760 Patent, discussed at paragraphs [174] to [189] below, and the term in proportion to in the ’345 Patent, discussed at paragraphs [344] to [355]—reference to the disclosure is necessary to resolve an ambiguity in the claim itself. In all other cases, referring to the disclosure simply “confirms” the construction arrived at in considering the claims: Tetra Tech at para 86.